Optical networking, including fiber-optics and optoelectronics, is an important aspect of high speed communication systems, particularly for its ability to allow for efficient, accurate, and rapid transmission of data between various components in the network system. As with most communication systems, the efficient use of space and power in optical networks is of ever-increasing importance. Further, design considerations for such networks must take into account the modularity of the particular components that are included in the network.
Indeed, modular components are desirable in fiber optic systems to reduce the cost of manufacturing the system, which increases the more customized the system becomes. An example of a modular component is an optical receiver module, which may also be a portion of a complete optical transceiver assembly (including both an optical transmitter module and an optical receiver module), or an optical transponder further comprising wavelength multiplexing/demultiplexing. A typical optical receiver module includes an input port/channel for an optical fiber (or other light propagating arrangement), a photodiode for detecting the incoming optical signals, and a sensing circuit for converting the optical signals to digital electrical signals compatible with other network components.
The number and placement of these elements of an optical receiver has heretofore limited the ability to reduce the size of the receiver, as well as its cost and complexity. For example, optical alignment between an incoming optical signal (usually along an optical fiber) and a photosensitive device has typically required “active” alignment, with the placement of the photosensitive device being maneuvered until a maximum optical power is detected. In high speed optical receivers, the photosensitive device generally exhibits a relatively small active area (in order to more efficiently convert the optical signal into its electrical counterpart). This small active area makes the process of performing an active alignment even more difficult.
Thus, a need remains in the art for an optical receiver module that is truly compact and allows for the use of passive alignment between the incoming optical signal and the photosensitive receiving device.